1. Field of the Invention
The present invention relates to a cooling and heating water circulation apparatus of a Vuilleumier heat pump for allowing a low temperature heat exchanger to absorb heat from a combustion unit during heating to thereby maintain a predetermined Coefficient of a Performance (COP) regardless of variations in outdoor temperatures, so that heating efficiency can be improved.
2. Description of Prior Art
Generally, the Vuilleumier heat pump comprises cylinders having three spaces of respectively different temperatures, the spaces being filled with gases such as helium, hydrogen or the like in high pressure, and the cylinders being provided with a high-temperature displacer and a low temperature displacer moving back and forth with a predetermined phase difference therein. The displacers shift the gases within a predetermined cycle to thereby cause pressure changes of gases according to the temperature changes, so that cooling and heating can be accomplished by way of heat discharge produced from the gases and heat absorption from the gases.
FIG. 1 is one embodiment of a cooling and heating water circulation apparatus of a conventional Vuilleumier heat pump.
According to FIG. 1, the Vuilleumier heat pump is disposed with a perpendicularly-related high temperature cylinder 2 and a low temperature cylinder 3 and a driving chamber 100 at which the two cylinders 2 and 3 meet.
The two cylinders 2 and 3 are filled with such gases as helium, hydrogen or the like in high pressure.
The high temperature cylinder 2 and the low temperature cylinder 3 are provided with a high temperature displacer 202 and a low temperature displacer 302 respectively, thereby separating the high temperature cylinder 2 into a high temperature chamber 200 and a mid temperature chamber 201, and separating the low temperature cylinder 2 into a mid temperature chamber 301 and a low temperature chamber 300.
The driving chamber 100 is provided with a motor 110, an axis of which is fixed with a crank shaft 120.
The crank shaft 120 is connected to the two displacers 202 and 302 through connecting rods 203 and 303.
Accordingly, when the motor 110 rotates, the crank shaft 120 in turn rotates and according to the rotation of the crank shaft 120, the connecting rods 203 and 303 perform a linear motion to thereby move back and forth the high and low temperature displacers 202 and 302.
At this time, the high and low temperature displacers 202 and 302 maintain a predetermined phase difference therebetween and move back and forth.
In other words, the two displacers 202 and 302 move reciprocatively in opposite directions relative to each other.
Meanwhile, a high temperature heat regenerative means comprising a high temperature heat regenerator 220 and a mid temperature heat exchanger 230 is disposed between the high temperature chamber 200 and the mid temperature chamber 201 on the high temperature side or section of the heat pump.
A low temperature heat regenerative means comprising a low temperature regenerator 320, a mid temperature heat exchanger 330 and a low temperature heat exchanger 310 is disposed between the mid temperature chamber 301 on the low temperature side and the low temperature chamber 300.
The high temperature heat regenerator 220 and the low temperature heat regenerator 32 are inter-connected, through a connecting tube, and the high temperature chamber 200 and the high temperature heat regenerator are interconnected by a high temperature heat exchanger 210.
The high temperature heat exchanger 210 passes through a combustion chamber 400 in a combustion unit 4, wherein gas passing through the high temperature heat exchanger 210 is heated by a burner 410.
The gas in the cylinders 2 and 3 is moved by a reciprocating motion of the high temperature displacer 202 in order of the high temperature chamber 200.fwdarw.high temperature heat exchanger 210.fwdarw.high temperature regenerator 220.fwdarw.mid temperature heat exchanger 230 on the high temperature side.fwdarw.mid temperature chamber 201 on the high temperature side, and then is moved in turn in order of mid temperature chamber 201 on the high temperature side.fwdarw.mid temperature heat exchanger 230 on the high temperature side.fwdarw.high temperature regenerator 220.fwdarw.high temperature heat exchanger 210.fwdarw.high temperature chamber 200.
According to a reciprocating motion of the low temperature displacer 302, the gas is moved in order of the mid temperature chamber 301 on the low temperature side.fwdarw.mid temperature heat exchanger 330 on the low temperature side.fwdarw.low temperature regenerator 320.fwdarw.low temperature heat exchanger 310.fwdarw.low temperature chamber 300, and then is moved in turn in order of the low temperature chamber 300.fwdarw.low temperature heat exchanger 310.fwdarw.low temperature regenerator 320.fwdarw.mid temperature heat exchanger 330 on the low temperature side.fwdarw.mid temperature chamber 301 on the low temperature side.
Here, the high temperature regenerator 220 extracts the heat from the gas moving from the high temperature chamber 200 to the mid temperature chamber 201 on the high temperature side to accumulate the heat, and then pre-heat the gas moving from the mid temperature chamber 201 on the high temperature side to the high temperature chamber 200.
The low temperature regenerator 320 accumulates the heat of the gas moving from the mid temperature chamber 300 on the low temperature chamber to the low temperature chamber 300 and then pre-heats the gas moving from the low temperature chamber 300 to the mid temperature chamber 301 on the low temperature side.
A conventional cooling and heating water circulation apparatus for cooling and heating indoors by way of the Vuilleumier heat pump comprises four-way valves FV1 and FV2, an indoor heat exchanger 6 and a convection fan F1 disposed indoors, an outdoor heat exchanger 7 and a cooling fan F2 disposed outdoors, a cooling water pipe CL penetrating an inner part of the low temperature heat exchanger 310, a heating water pipe HE penetrating inner parts of the mid temperature heat exchangers 230, 330, an indoor connecting water pipe L1 and circulation pump P2 of the indoor heat exchanger 6, and an outdoor connecting water pipe L2 and a circulation pump P1 of the outdoor heat exchanger 7, so that the cooling and heating water can be circulated to respective indoor and outdoor heat exchangers 6 and 7.
In other words, for the cooling operation, the four-way valves FV1 and FV2 are operated (driven) to interconnect the cooling water pipe CL and the indoor connection water pipe L1 and to interconnect the heating water pipe HL and the outdoor connecting water pipe L2.
At this time, the cooling water cooled in the process of passing through the low temperature heat exchanger 310 has cooled the room interior in the course of its circulation to the indoor heat exchanger 6, and the heating water heated (or heat-absorbed) in the process of passing through the mid temperature heat exchangers 230, 330 discharges the heat in the course of its circulation through the outdoor heat exchanger 7.
Meanwhile, for the heating operation, the four-way valves FV1 and FV2 are operated (driven) to interconnect the cooling water pipe CL and the outdoor connecting water pipe L2 and to interconnect the heating water pipe HL and the indoor connecting pipe L1.
At this time, the heating water heated (or heat-absorbed) in the process of passing through the mid temperature heat exchangers is circulated to the indoor heat exchanger 6 to heat the room interior, and the cooling water which has passed through the low temperature heat exchanger 310 is circulated to the outdoor heat exchanger 7 to thereby absorb heat.
However, in the above description, the heating is usually executed during the winter time, and during this time, because the outdoor temperature is very low and the heat absorbed by the outdoor heat exchanger 7 is insufficient, the quantity of heat at the low temperature heat exchanger 310 is relatively reduced.
Because of the insufficiency of heat absorbed at the outdoor heat exchanger 7 to thereby allow the cooling water of low temperature to be circulated to the low temperature heat exchanger 310, the temperature at the low temperature chamber 300 drops, thereby reducing a heating Coefficient of Performance COP, which can be explained in the following formula. EQU COPc=(TH-TA/TH) (TC/TA-TC) Formula 1 EQU COPh=1+COPc Formula 2
Where, COPc=cooling COP, COPh=heating COP, TH=temperature at the high temperature chamber 200, TA=temperatures of mid temperature chambers 201, 301, and TC=temperature at the low temperature chamber 300, and the temperatures mentioned in the above formulae denote the absolute temperatures.
As seen in the formula 1, it should be apparent that when the temperature TC of the low temperature chamber 300 drops, the cooling COP (COPc) is reduced, and when the cooling COP (COPc) is reduced, the heating COP (COPh) is also reduced.
In other words, there has been conventionally a drawback in that the temperature TC at the low temperature chamber 300 drops due to the low outdoor temperature under weather calling for substantially greater heating load to thereby cause the heating COP (COPh) to deteriorate.
Meanwhile, for example, in Japanese laid open patent application No Hei 4 (1992) - 113175 entitled, "Heating device", an auxiliary heating device is provided which comprises an externally fired engine driven by heat from a combustor. A medium heated by a radiating heat exchanger of the externally fired engine flows, to the indoor heat exchanger. An exhaust heat retrieving heat exchanger for retrieving exhaust heat from the combustor is disposed on a pipe which conducts the medium from the radiating heat exchanger to the indoor heat exchanger.
According to the Japanese laid open patent application No. Hei 4 (1992) - 113175, the heated medium discharged from the radiating heat exchanger is reheated in the exhaust heat retrieving heat exchanger before being introduced into the indoor heat exchanger, so that heating capacity is improved and at the same time, a high exhaust heat retrieving efficiency is achieved due to the presence of the exhaust heat retrieving heat exchanger.
In other words, as described, when the input heat is assumed as having a value of 100, and discharged heat is assumed as having a value of 20, the heat retrieved from the discharged heat can have a value 6.
However, the aforesaid apparatus has a drawback in that the retrieval of exhaust heat from the combustor for directly supplying the same to the indoor heat exchanger for use not only achieves less retrieval efficiency of the waste heat but also contributes absolutely no effect on improving the efficiency of the Vuilleumier heat pump.